Stock-based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands					1 Months Ended						3 Months Ended		6 Months Ended	9 Months Ended		48 Months Ended
	Mar. 16, 2023 USD ($) trading_day tranche $ / shares	Jan. 01, 2023 shares	Aug. 19, 2022 $ / shares shares	May 02, 2022 $ / shares shares	Aug. 31, 2023 shares	May 31, 2023 USD ($) shares	Aug. 31, 2022 USD ($) shares	Jun. 30, 2022 shares	Apr. 30, 2022 USD ($)	Aug. 31, 2021 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2019	Sep. 30, 2023 USD ($) trading_day $ / shares shares	Sep. 30, 2022 USD ($)	Jun. 30, 2023 shares	Dec. 31, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of stock options exercised | $														$ 7,400
Fair value of options vested | $														$ 1,600
Shares issued upon vesting of each RSU											1			1
Stock-based compensation expense | $											$ 44,882	$ 52,551		$ 160,031	$ 117,874
Optogration Milestone Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contingent stock consideration | $										$ 22,000
Freedom Photonics Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contingent stock consideration | $									$ 29,800					20,900
Class A Common Stock | Optogration Milestone Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based arrangement awards (in shares) | shares					1,527,788		1,632,056
Share-based arrangement awards | $							$ 11,000
Share-based arrangement awards, remaining obligations | $											11,000			$ 11,000
Class A Common Stock | Freedom Photonics Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based arrangement awards (in shares) | shares						634,994
Share-based arrangement awards | $						$ 3,900
Stock-based awards—Liability classified | Share-based Payment Arrangement, Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years and in months)													4 years
Granted (in shares) | shares																0
Stock-based awards—Liability classified | Tranche One | Share-based Payment Arrangement, Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage													25.00%
Stock-based awards—Liability classified | Tranche Two | Share-based Payment Arrangement, Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years and in months)													36 months
Award vesting percentage													75.00%
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) | shares														19,351,770
RSUs | Freedom Photonics Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based arrangement awards (in shares) | shares						492,176
Share-based arrangement awards | $						$ 3,500
RSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years and in months)														6 years
Management awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) | shares														370,000
Management awards | Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) | shares				10,800,000
Grant date fair value (in dollars per share) | $ / shares				$ 8.70
Management awards | Chief Legal officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) | shares			500,000
Grant date fair value (in dollars per share) | $ / shares			$ 6.12
Management awards | Chief Financial Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) | shares			500,000
Grant date fair value (in dollars per share) | $ / shares			$ 6.12
Management awards | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense | $											5,600			$ 16,900
Grant date fair value (in dollars per share) | $ / shares	$ 8.58
Consecutive trading days | trading_day														90
Service period (in years)	7 years													7 years
Granted | $	$ 12,000
Fair value of restricted stock vested | $	$ 2,000
Number of tranches | tranche	6
Trading days | trading_day	90
Management awards | Tranche One | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting, market condition, stock price (in dollars per share) | $ / shares	$ 20
Management awards | Tranche Two | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting, market condition, stock price (in dollars per share) | $ / shares	25
Management awards | Tranche Three | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting, market condition, stock price (in dollars per share) | $ / shares	30
Management awards | Tranche Four | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting, market condition, stock price (in dollars per share) | $ / shares	40
Management awards | Tranche Five | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting, market condition, stock price (in dollars per share) | $ / shares	50
Management awards | Tranche Six | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting, market condition, stock price (in dollars per share) | $ / shares	$ 60
Management awards | Achievement of stock price one | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting, market condition, stock price (in dollars per share) | $ / shares														$ 50
Management awards | Achievement of stock price two | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting, market condition, stock price (in dollars per share) | $ / shares														60
Management awards | Achievement of stock price three | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting, market condition, stock price (in dollars per share) | $ / shares														$ 70
2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance (in shares) | shares																	36,588,278
2020 Plan | Equity-settled fixed value | Share-based Payment Arrangement, Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years and in months)														4 years
Stock-based compensation expense | $											$ 4,200	$ 1,900		$ 10,100	$ 5,400
Amended 2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized for issuance (in shares) | shares								36,000,000
Percentage of outstanding stock maximum								5.00%
Incremental number of shares authorized (in shares) | shares								40,000,000
Amended 2020 Plan | Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized for issuance (in shares) | shares		18,358,365
2015 Plan | Stock-based awards—Equity classified
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years and in months)														4 years
Award expiration period (in years)														10 years
2015 Plan | Stock-based awards—Equity classified | Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage														25.00%
2015 Plan | Stock-based awards—Equity classified | Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years and in months)														36 months
Award vesting percentage														75.00%